Australia and Gondwanaland

Along the western margin of the Australian continent there exist four major sedimentary basins, filled with predominantly marine rocks from Cambrian to Tertiary in age, and up to 40,000 feet thick. Seaward these basins continue into depressions recognizable in the continental shelf and even the continental slope. Their very presence, the nature of their sediments and the composition and relationships of their fossil faunas indicate the existence of an open ocean to the west of Australia since early Paleozoic time. Composition of the Australian fossil land vertebrate faunas suggests isolation of the Australian continent since at least Permian time.A condensed version of this paper was presented at the XX International Geological Congress in Mexico, September 1956. Publication authorized by the Director, U. S. Geological Survey.The writer is greatly indebted to B. E.Balme, B. F.Glenister, A. W.Lindner, J. R. H.McWhae, and P. E.Playford for brief summaries of important new stratigraphic and paleontological studies. These were communicated to the writer by B. F.Glenister and are, in their proper places, acknowledged asMcWhae et al., ms. In the meantime this work appeared under the title Stratigraphy of Western Australia in Jour. Geol. Soc. Australia, vol. 4, pt. 2, 1958, p. 1–161, after the present paper had gone to press. For stratigraphical details the reader is referred to this authoritative publication.